Summary

Monsterkind emerging from Mount Ebott had been met with immediate racism and hatred. Taken as slaves, Sans couldn’t stay with his human owner when he knew Papyrus was in danger. The magic suppression collar could kill him any moment. Taking a leap of faith that he believed would be his last, instead he found a possible way to freedom in the most unlikely of places with the most unlikely of monsters.

Summary

All is finally peaceful in the Undertale universe and Sans had rediscovered his passion for science. After a new breakthrough with Doctor Alphys at the lab, inter-dimensional travel is not only feasible but has gotten results. The skeleton monster dives through the fabric of space and time to discover an Underground breathtakingly different from his own.

In Undercarnal, monsters had nearly wiped each other to extinction. Everyone here is a towering and feral version of the friends and family Sans knew. One in particular has taken a keen interest in his exploration and study.